Push-button switch assembly



Febf15, 1943- H. M. ZIMMERMAN l-:TAL 2,311,322

PUSH BUTTON SWITCH ASSEMBLY Filed May 6, 1941 32 25 35 10 22 lNvEN-roRs Henry M. Zimmerman 1 J l BYg -Ptlh ATTO R N EY Patented Feb. 16, 1943 PUSH-BUTTON SWITCH ASSEMBLY Henry M. Zimmerman and George 0. Puerner, Indianapolis, Ind., assignors to P. R. Mallory & Co., Inc., indianapolis, Ind., a corporation of Delaware Application May 6, 1941, Seriai No. 392,046

(Cl. 'i4-433) 4 Claims.

This invention relates to push button switches and parts thereof.

An object of the inventionis to improve push button switches and parts thereof.

`Other objects of the invention will be apparent from the following description and accompanying drawing taken in connection with the appended claims.

The invention comprises the features of construction, combination of elements, arrangement of parts, and methods of manufacture and operation referred to above or which will be brought out and exemplified in the disclosure hereinafter set forth, including the illustrations in the draw- In the drawing:

lFigure 1 is a top View of a push button switch embodying features of the present invention;

Figure 2 is a section on the line 2 2 of Figure Figure 3 is a section on the line 3 3 of Figure 2;

Figure 4 is a section on the line 6 4 of Figure 3.

Figure 5 is a section on the line 5 5 of Figure 3; and

Figure 6 is a detailed View illustrating the operation of part of the switch.

The present invention is particularly applicable to push button switches wherein it is desired to have individually latching plungers so that one or more of the plungers may be latehed up independently without disturbing the remaining plungers while all may be released simultaneously under control of a single plunger.

In its preferredV form the invention is applied to a push button switch of the type having several push rods slidably supported side by side in a frame with individual springs biasing each of the push rods toward the front of the frame. A co l.- mon latch bar is provided having a latching abutment individual to each of the push rods for latching them in operated position against the force of their respective biasing springs. The preierred switch of the present invention is chara cterized by the fact that one or more of the push rods has an individual latching arm pivcted thereon and biased by the same spring which biases the push rod into latching position with respect to the abutment on the latch bar. One of the push rods is differently constructed for control oi the latch bar so that by operation of this push rod, the remaining push rods may be released if they are in latched position at the time. It is thus possible to operate one or more of the individual plungers whereupon they will be held in operated position by their individual latching arms in co-operation with the common latch bar until such time as they are all simultaneously released by the releasing plunger.

While a preferred embodiment of the invention is described herein, it is contemplated that considerable variation may be made in the method of procedure and the construction of parts without departing from the spirit of the invention. In the following description and in the claims, parts will be identified by specific names, for convenience, but they are intended to be as generic in their application to similar parts as the art will permit.

Referring to the drawing, there is illustrated a push button switch comprising a frame formed of a front sheet metal channel member l0, a rear plate ll, and end plates or channel members l2 and i3, all riveted together to form a rectangular frame. The push rods or plungers I4, l5 and I6 are mounted therein through aligned slots in the front and rear plates l0 and Il so as to be slidable in the frame by pressure against push buttons l1, I3 or i9 attached respectively to the forward ends of the rods. The push rods have widened portions between the front and rear plates such as portion 26 of rod I4, these widened portions having longitudinal slots or windows 2| therein.

A common latch bar 22 passes through these slots and aligned slots in end plates l2 and I3. Latch bar 22 has cut out portions providing latching abutments or cam surfaces 23 thereon individual to each push rod at the point where the latch bar passes through the rod. A biasing spring 24 urges latch bar 22 and consequently cam surfaces 23 into latching engagement with the plungers, stop 25 limiting the travel of the latch bar.

A terminal strip 26 of sheet insulating material is mounted against one face of the switch frame and secured thereto by bent over ears 21 comprising part of end walls I2 and I3. This terminal strip carries contact terminals 23 for cooperation with contacts carried by the individual push rods. For example, push rod i4 carries a small block of sheet insulating material 29 at one edge of widened portion 2l] and a contact 30 is supported therein for cooperation with stationary contact `'128. The contacts and their supporting strips of sheet insulating material are shown in Figures 2 and 3 only since the present invention is concerned particularly with the operation of the plungers and latching means therefor.

In the switch illustrated, plungers I4 and I5 are constructed to be individually latching whereby they may be individually depressed and latched up without disturbing the condition of the remaining plungers. Plunger |'6 is a common release plunger, which upon operation, moves latch bar 22 out of latching engagement with any of the other plungers which happen to be latched up.

Referring to the individually latching plunger I 4. it carries a latching arm or hook 3| formed of a stamping of sheet metal having a pair of hooks 32 thereon which hook around the rear corners of widened portion 20 of the push rod so that these corners provide a pivot for arm 3|. 'I'he arm also has an ear 33 thereon eX- tending in the opposite direction from hooks 32 at the rear end of the arm. A coil bias spring 34 surrounds the rear end of push rod I4 between ear 33 and rear plate II of the switch. This plunger return spring performs two functions, namely to urge the push rod I4 toward the front of the switch and to urge latch arm 3| to rotate about its pivot point 35 until it lays against the side of the push rod. The free end of latching arm 3| is bent at right angles through window 2| of thelpush rod thereby forming a latching hook which is so positioned as to slide over the cam surface 23 of the latch bar when the plunger is depressed. Latching arm 3| is also provided with a window 35 through which latch bar 22 passes.

Plunger I5 is arranged similarly to plunger It. Plunger I6, however, does not have a latch arm pivoted thereon but instead has a shorter window 31 therein so that the rod itself engages the cam 'surface 23 when plunger I6 is depressed against the pressure of its spring 38.

Thebias on latching'arm 3| is weaker than that given latch bar 22 by its spring 24, and Z0 hence upon depression of either plunger Illor l5 the latch bar is not affected but instead ylatching arm 3| will be rotated against the bias applied by spring 34 to allow its hook end to slide over the cam surface 23 and latch with this abutment when the push rod reaches operated position. When plunger |5 is operated, however, the latch bar 22 is moved longitudinally against its` spring bias to release plunger i4 or I5 if they are in operated position.

It will be apparent from the above description that any number of plungers having Vmeans for individually latching them may be mounted in a single switch unit under control of a common releaseplunger. It is also apparent that two or more release plungers may be provided as desired.

'The switch of the type described finds application in numerous ways such as in testing equipment, meter controls, radio sets and similar electrical apparatus.

While the present invention, as to its objects and advantages, has been described herein as carried out in specific embodiments thereof, it is not desired to be limited thereby but it is intended to cover the invention broadly within the spirit and scope of the appended claims.

What is claimed is:

l. A push button switch wherein a push rod is slidably supported in a frame and a spring urges said rod toward one end of its path of confined travel therein and a latch bar having a latching abutment thereon is also mounted in said frame and is movable to bring said abutment into and out of latching position, characterized by the fact that there is combined with said push rod a latching arm pivoted thereon and biased by said spring toward said latching abutment on said latch bar to latch therewith when said p-ush rod reaches a predetermined position in its path of travel.

2. In a push button switch of the class wherein a push rod is slidably supported in a frame and a spring urges said rod toward one end of its path of conned sliding travel therein and a latch bar having a latching abutment thereon is also mounted in said frame and is movable to bring said abutment into and out of latching position, the combination with said push rod of a latching arm pivoted thereon and biased by said spring toward said latching abutment on said latch bar to latch therewith when said push rod is moved a predetermined distance against the force of said spring.

3. A sub-assembly for a push button switch, said sub-assembly comprising, in combination, a push rod for controllingsaid switch contacts, a latching arm pivoted thereon and having a latching portion for latching with an abutment on said switch, and a common biasing spring biasing said push rod toward one end of its path of conned travel and also biasing said latching portion toward its position for latching with said abutment.

4. A sub-assembly for an individually latching push button switch, said sub-assembly comprising in combination apush rod, a latching arm pivoted thereon, part of said rod being in the path of rotation of said latching arm about its pivot whereby to limit the movement of said latching arm about said pivot, and a spring engaging said latching arm at a point offset from said pivot and applying spring pressure in a direction substantially parallel to said push rcd whereby to urge said push rod toward one end of its direction of sliding travel, said spring also applying a rotational torque to said latching arm urging said arm against said push rod. i

HENRY M. ZIMMERMAN. GEORGE O. PUERNER. 

